Current Status of Diagnostic Process in Asymptomatic Abdominal Aortic Aneurysm in Japan

<b>Objectives:</b> This study aimed to investigate the actual detection process and diagnostic methods for asymptomatic abdominal aortic aneurysm (AAA) in a multicenter setting, and to plan an effective screening strategy for asymptomatic AAA. <b>Methods:</b> The subjects of this multicenter study were collected in a retrospective manner at 7 facilities. A total of 1894 patients with AAA, including iliac artery aneurysms, who were considered asymptomatic with a confirmed initial diagnosis from January 2018 to December 2022, were collected and reviewed. <b>Results:</b> A total of 1666 patients who were diagnosed with asymptomatic AAA were included [83.9% males, median age of 75 (69-81) years]. Asymptomatic AAAs were frequently diagnosed during examinations for other diseases in 1339 patients (80.4%), whereas health screenings accounted for only 313 (18.8%). Computed tomography (CT) was the most commonly used diagnostic method (n = 1352, 81.2%) compared to abdominal ultrasonography (n = 252, 15.2%). <b>Conclusions:</b> Asymptomatic AAAs are detected incidentally during examinations for other diseases, and there is an urgent need to promote health screening. Most AAAs are diagnosed by CT; nevertheless, we consider that abdominal ultrasonography would be the most appropriate modality for AAA screening because of its reasonable accuracy, noninvasiveness, and low cost.